Latanoprost ((isopropyl (Z)-7-[(1R,2R,3R,5S)-3,5-dihydroxy-2-[(3R)-3-hydroxy-5-phenylpentyl]-cyclopentyl]hept-5-enoate) is an isopropyl ester analogue of prostaglandin F2α.

The commercially available form of latanoprost (XALATAN®) includes no cyclodextrin and has issues concerning formulation stability. Latanoprost has been demonstrated to undergo substantial UV-B (320 nm to 290 nm) catalyzed photolytic degradation even under short exposure time, and it has been demonstrated to undergo substantial thermal and/or hydrolytic degradation at elevated temperatures in a pH dependent manner. The commercial formulation also contains BAK (benzalkonium chloride; 0.02%) as preservative; however, BAK has been reported to lead to corneal damage, and such activity is counterproductive to the therapeutic activity of latanoprost.
Sulfoalkyl ether cyclodextrin (SAE-CD) derivatives are polyanionic, hydrophilic, water soluble cyclodextrins derivatized with sulfoalkyl ether functional groups. SAE-CD derivatives are commercially available from CyDex Pharmaceuticals, Inc. (Lenexa, Kans.). SAE-CD is currently marketed under the trademarks CAPTISOL® and Advasep®.
CAPTISOL® has an average of about 7 sulfoalkyl ether substituents per cyclodextrin molecule. The anionic sulfobutyl ether substituent dramatically improves the aqueous solubility and safety of the parent cyclodextrin. Reversible, non-covalent, complexation of drugs with CAPTISOL® generally allows for increased solubility and, in some cases, increased stability of drugs in aqueous solutions.
